1. Field of the Invention
The present invention relates to a turn control apparatus for stabilizing the turning behavior of a motor vehicle when the vehicle makes a turn, and, more particularly, to a turn control apparatus for a motor vehicle, which has excellent cooperation with an antiskid braking system.
2. Description of the Related Art
This type of turn control apparatus for a motor vehicle is disclosed in, for example, Japanese Unexamined Patent Publication No. 5-24528. This known apparatus comprises detection means for detecting the steered angle of wheels; first speed detection means for detecting a vehicle speed; second speed detection means for detecting wheel speeds of the individual wheels; setting means for setting a target kinetic value of the vehicle based on the steered angle of the wheels and the vehicle speed; first computing means for computing a first target braking force for controlling the actual kinetic value of the vehicle to match the target kinetic value; second computing means for computing a second target braking force based on speeds of the right and left wheels and the vehicle speed to establish a predetermined slip to the wheels; and brake control means for selecting a smaller one of the first and second target braking forces as a final target braking force and controlling the actual braking forces of the right and left wheels of the vehicle independently of the final target braking force.
Specifically, when the first target braking force is selected as the final target braking force while a vehicle is turning, the known control apparatus controls the braking forces of the wheels or the yaw moment of the vehicle in such a way as to match the actual yaw rate of the vehicle with the target yaw rate. Consequently, the turning behavior of the vehicle while making a turn is stabilized. When the second target braking force is selected as the final target braking force, on the other hand, the known control apparatus controls the braking forces of the wheels in such a way that the actual slip coincides with the target slip. That is, the braking forces of the wheels are adjusted on the basis of the antiskid brake control.
According to the aforementioned known turn control apparatus, however, either the first target braking force or the second target braking force is simply selected as the final target braking force, so that the antiskid brake control does not work when the yaw moment of the vehicle is controlled, and the yaw moment control of the vehicle does not work when the antiskid brake control is effective.